Question: $J$ $K$ $L$ If: $ JK = 5x + 7$, $ JL = 141$, and $ KL = 9x + 8$, Find $KL$.
From the diagram, we can see that the total length of ${JL}$ is the sum of ${JK}$ and ${KL}$ $ {JK} + {KL} = {JL}$ Substitute in the expressions that were given for each length: $ {5x + 7} + {9x + 8} = {141}$ Combine like terms: $ 14x + 15 = {141}$ Subtract $15$ from both sides: $ 14x = 126$ Divide both sides by $14$ to find $x$ $ x = 9$ Substitute $9$ for $x$ in the expression that was given for $KL$ $ KL = 9({9}) + 8$ Simplify: $ {KL = 81 + 8}$ Simplify to find ${KL}$ : $ {KL = 89}$